package NC;

public class NC39 {
    private int ans = 0;
    public int Nqueen (int n) {
        // write code here
        backtrace(n,0,n);
        return ans;
    }
    public void backtrace(int n,int now,int leave){
        if(leave<0) return;
        if(leave==0) return;

    }
}
